Offshore driller CNOOC Ltd said its Nexen Inc purchase has received "extremely positive" feedback from both companies' workers and management.

The State-owned oil and gas company completed its $15.1 billion takeover of the Canadian oil and gas company late last month, in the largest overseas acquisition by a Chinese company.

The deal took over a year to complete, as regulators in the US and Canada reviewed whether the acquisition violated their national interests and safety - concerns fueled by CNOOC's State ownership.